WO2010100077A1 - Method for enhancing the handover of a mobile station and base station for carrying out the method - Google Patents

Method for enhancing the handover of a mobile station and base station for carrying out the method Download PDF

Info

Publication number
WO2010100077A1
WO2010100077A1 PCT/EP2010/052425 EP2010052425W WO2010100077A1 WO 2010100077 A1 WO2010100077 A1 WO 2010100077A1 EP 2010052425 W EP2010052425 W EP 2010052425W WO 2010100077 A1 WO2010100077 A1 WO 2010100077A1
Authority
WO
WIPO (PCT)
Prior art keywords
base station
radio coverage
sl
sector
mobile station
Prior art date
Application number
PCT/EP2010/052425
Other languages
French (fr)
Inventor
Olivier Marce
Arnaud Petit
Van Minh Nguyen
Original Assignee
Alcatel Lucent
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to EP09305189.4A priority Critical patent/EP2227056B1/en
Priority to EP09305189.4 priority
Application filed by Alcatel Lucent filed Critical Alcatel Lucent
Publication of WO2010100077A1 publication Critical patent/WO2010100077A1/en

Links

Classifications

    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/24Reselection being triggered by specific parameters used to improve the performance of a single terminal
    • H04W36/32Reselection being triggered by specific parameters used to improve the performance of a single terminal by location or mobility data, e.g. speed data
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/0005Control or signalling for completing the hand-off
    • H04W36/0055Transmission and use of information for re-establishing the radio link
    • H04W36/0061Transmission and use of information for re-establishing the radio link of neighbor cell information
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W36/00Hand-off or reselection arrangements
    • H04W36/08Reselecting an access point
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W48/00Access restriction; Network selection; Access point selection
    • H04W48/20Selecting an access point
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04WWIRELESS COMMUNICATION NETWORKS
    • H04W64/00Locating users or terminals or network equipment for network management purposes, e.g. mobility management
    • H04W64/006Locating users or terminals or network equipment for network management purposes, e.g. mobility management with additional information processing, e.g. for direction or speed determination

Abstract

The invention concerns a method for enhancing the handover of a mobile station (20-23) from a serving base station (1) of a cellular network to a new base station, the new base station is selected among a neighbor list including neighboring base stations, the radio coverage cell (r2-r8) of which overlaps the radio coverage cell (r1) of said serving base station (1). It is also provided the base station for carrying out the method. According to the invention it is determined a current sector (s1-s3; s1-s6) in which said mobile station (20- 23) is located among a plurality of sectors (s1-s3; s1-s6) partitioning the radio coverage cell (r1) of said serving base station (1), and the neighbor list includes only the neighboring base stations the radio coverage cell (r2-r8) of which overlaps said current sector (s1-s3; s1-s6).

Description

Method for enhancing the handover of a mobile station and base station for carrying out the method

The invention relates generally to wireless communications, in particular, to a method for enhancing the handover of a mobile station from a serving base station of a cellular network to a new base station. The invention also relates to a particular base station for the implementation of the method.

A communication performed from a mobile station implies that the mobile station is located in the radio coverage cell of a base station. The base station performing radio exchanges with the mobile station so that it can perform the communication is commonly called the serving base station.

However, during a communication, cellular network may have to perform transfers of the communication from a serving base station to a new base station, in order to avoid loosing a call when, for instance, the mobile station gets outside the area covered by the serving base station.

This automatic transfer of the communication from the serving base station to a new base station is called handover.

With system based on large cells, the probability that a handover event occurs during a communication is small. However, the achievement of high capacities for transmitting both voice and data communications with very high throughput has required a continuous reduction of cells size. Therefore, it is very common that one or even a plurality of handovers occurs during a communication performed by a user through his mobile station.

A handover is necessary when a mobile station carrying out a communication is getting out of the serving base station or if no capacity is remaining in the cell associated with the serving base station for connecting a new communication.

More precisely, a mobile station carrying out a communication periodically performs quality and power measurements to determine if the channel conditions associated with the serving base station are satisfactory. The measurement results are transmitted in parallel of the communication to the base station. If the results indicate that the quality of the transmission is to much altered or that a too high power is needed to transmit signals to the serving base station, the serving base station gets the mobile station to perform a handover to another base stations.

Alternatively, the serving base station can detect that no capacity is remaining in its associated cell for connecting a new communication and thus prompts some mobile stations which are currently using it to perform a communication, to carry out a handover to a new base station. A handover typically includes two phases. The first phase, commonly called observation phase, is used to select a base station neighboring the current serving base station which is the most appropriate to continue the communication with the mobile station. The second phase consists in automatically transferring the communication to the selected base station. The fact that the communication performed from the mobile station must not be altered during the handover leads the two above quoted phases to be carried out in a very short delay.

During the observation phase, the mobile station measures, for each base station of a specific list, the signal strength which it receives from the base station. This specific list, currently named neighbor list, is transmitted to the mobile station by the serving base station when this one prompts the mobile station to perform an observation phase. The list comprises all the neighboring base stations such that the coverage area of which overlap the coverage area of the serving station. Each signal strength measured by the mobile station is sent to the serving base station which then selects, according to the result of the measurements performed and sent by the mobile station in combination with other knowledge of the cellular network, the new base station among the base stations most adapted to continue the communication. The communication is then automatically transferred to the selected base station.

The selection of the new station is facilitated when strength signal measurements are performed with accuracy.

Actually, the neighbor list comprises all the neighboring base stations the coverage of which overlap the coverage area of the serving base station. Consequently, the number of station comprised in the list may be high and it leads the mobile station to perform a large number of strength signal measurements. This is specifically the case in urban area in which the cells have small sizes.

A minimum of delay is necessary to perform each strength signal measurement with a satisfactory accuracy. Consequently, when a serving base station has a great number of neighboring bases stations, the observation phase may take a long time to be correctly performed. However, as mentioned above, the observation phase has to be carried out in the shortest delay as possible.

This situation leads either to extend the delay of the observation phase in order to enable the mobile station to perform all the measurements with a sufficient degree of accuracy or to perform the selection of the new base station from measurements of lesser accuracy. Both alternatives are not satisfactory to ensure handover of the communication without risking to alter or to lose the communication.

Document WO 99/27657 discloses a method for enhancing the handover of a mobile station according to the preamble of claim 1. Other method are known, such as the method disclosed in Document

US 7 092 722 for cellular network in which each cell is divided in a plurality of sectors, for instance three sectors arranged as pie pieces, thanks to the use of a plurality of directional antennas or antenna components for the respective base station. The aim of the present invention is to enable the handover of a mobile station in a short delay while enabling the mobile station to perform accurate strength signal measurements.

In a first aspect it is provided a method for enhancing the handover of a mobile station from a serving base station of a cellular network to a new base station, as claimed in claim 1.

When the radio coverage cell of the serving base station corresponds to the radio coverage beam of at least one directional transmitting/receiving antenna, the radio coverage beam extending along a main axis, then the radio coverage beam is partitioned in a succession of ring portions extending concentrically with respect to said antenna along the main axis and each sector of the plurality of sectors partitioning the radio coverage beam corresponds to one of said ring portion. In this case, the current sector is determined based on an estimation of the distance between the mobile station and the antenna.

Alternatively, when the radio coverage cell of the serving base station corresponds to the radio coverage beam of at least one directional transmitting/receiving antenna, the radio coverage beam extending along a main axis, then the radio coverage beam is partitioned in a succession of ring portions extending concentrically with respect to the antenna along the main axis and each sector of the plurality of sectors partitioning said radio coverage beam corresponds to half part of one of said ring portion with respect to said main axis. In this case, the current sector is determined based on estimation of the angle and of the distance between said mobile station and said antenna.

In a second aspect it is provided a base station for carrying out the method disclosed in the first aspect. The base station is characterized in that it comprises: - tracing means adapted to determine a current sector in which is located said mobile station; and

- partitioning means adapted to include in said list only the neighboring base stations the radio coverage cell of which overlaps said current sector. The features and advantages of the invention will become more apparent from the following detailed description with reference to the attached figures wherein:

- Figures Ia and Ib represent, schematically, two examples of a radio coverage cell of a base station divided into a plurality of sectors according to the method of the invention.

- Figures 2a and 2b represent tables showing, for each sector disclosed respectively in figure Ia and Ib, the associated list of neighboring base stations computed according to the method of the invention. - Figure 3 represents, schematically, processing components located in a base station and their interactions for enabling a handover of a mobile station from the base station according to the method of the invention.

As shown in figure Ia a plurality of mobile stations 20, 21, 22, 23, 24 are located within the radio coverage cell rl of a base station 1. It is assumed that mobile stations 20, 21, 22 and 23 are presently in communication and that the communications are achieved by performing at least wireless transmissions/receptions with base station 1. Thus, base station 1 is considered as the serving base station for mobile stations 20, 21, 22 and 23. It is further assumed that mobile station 20 is moving and presently getting out of radio coverage rl during its communication. It is thus necessary to enable a handover of this mobile station from serving base 1 to one of the neighboring stations station without altering its communication.

For enabling the handover of mobile station 20 from serving base station 1 with an appropriate new base station, serving base station 1 transmits to mobile station 20 a list including neighboring base stations, each neighboring base station included in the list having its radio coverage r2, r3, r8 overlapping radio coverage rl of serving base station 1. Then, a new base station is selected among the neighboring base stations included in the list according to measures performed mobile station 20.

As already explained above, commonly applied method for enabling the handover of a mobile station uses a unique list comprising all the neighboring base stations of serving base station 1. More precisely, all mobile stations getting out of radio coverage cell rl receive same unique list and perform signal strength measures with all neighboring base stations.

The method according to the invention differs from the commonly applied method in that serving base station 1 transmits a list selected among a plurality of lists according to the location of the mobile station.

More precisely, as shown on figure Ia, radio coverage cell rl is divided into a plurality of sectors si, s2..., s3. For each sector si, s2, s3, it is computed a list which only includes the neighboring base stations which have their radio coverage cell overlapping the radio coverage cell rl of serving base station 1 within the sector. Before transmitting the list to the mobile station, the sector in which is located the mobile station is determined. Serving base station then transmits the list computed for the sector in which the mobile station is located. Since each computed list includes only a limited number of neighboring base stations, mobile base station is able to perform strength signals measures with all the neighboring base station included in the computed list in a short time and with a satisfactory accuracy.

Referring to figures Ia, Ib, 2a, 2b and 3, the various features involved in the division of the radio coverage cell into a plurality of sectors, the computation of a plurality of lists and the transmission of one list among the plurality of lists to the mobile station will be detailed in the case the serving base station comprises at least one directional antenna.

The present invention is in no way limited to the particular example embodiments explicitly shown in figures 1 and 2 and described herein. As shown on figure Ia, when serving base station 1 comprises at least one directional antenna (not shown) for transmitting/receiving wireless communications, the radio coverage cell rl corresponds to the transmission/reception diagram of the directional antenna. The diagram of such a directional antenna is approximately an ellipse which corresponds to the main lobe of the directional antenna. The main axis of the ellipse corresponds to the direction of the main lobe.

As shown on figure Ia, in this particular configuration, base station 1 is not located in the middle of the radio coverage cell rl but at one extremity of the ellipse, which corresponds to the location of the directional antenna. In this case, dividing radio coverage cell rl into sectors comprises defining a succession of circles c0, cl,..., cN the center of which is serving base station 1. Each circle of the successions of circles cl, c2,..., cl\l has a radius comprised between zero and the value corresponding to the broadcast range of the directional antenna in the direction of the main axis. For the purpose of a better understanding of the invention, it is considered that the first circle cO of the successions of circles has a radius equal to zero and consists in the point at which the base station is located. The last circle cN of the successions of circles has a radius equal to the broadcast range.

Each sector corresponds to the area defined as the intersection of the ellipse and the ring limited by two successive circles. In the particular example shown on figure Ia, a succession of four circles c0, cl,..., c3 has been defined and radio coverage area cell rl of serving base station 1 has been divided into three sectors si, s2, s3.

According to the method of the invention, after the sectors have been defined, for each sector, a particular list is computed. Each particular list, computed and associated to a sector, only includes the neighboring base stations which have their radio coverage cell overlapping the radio coverage cell rl of serving base station 1 within this sector.

Figure 2a represents a table comprising computed lists II, 12, 13 respectively associated with sectors si, s2 and s3 as illustrated on figure Ia. As shown in the table, sector si is associated with list Il including the neighboring base stations respectively associated with radio coverage cells r7, r8 and r2 since only these radio coverage cells overlap radio coverage cell rl in sector si. Similarly, list I2 associated with sector s2, includes the four neighboring base stations respectively associated with radio coverage cells r6, r7, r2 and r3 and list I3 computed for sector s3 only comprises the four neighboring base stations the radio coverage cells of which are respectively r3, r4, r5 and r6.

Advantageously, serving base station 1 may comprise a dedicated neighbor list computation module 10 which is in charge of computing the different lists once the sectors have been defined. Such a module 10 may have knowledge of the topology of the wireless network. More precisely, neighbor list computation module may be implemented with geographical information such that location of the neighboring base station and broadcast range of the antenna implemented in the neighboring base station. According to the geographical information, neighbor list computation module 10 determines the neighboring base stations the respective radio coverage cell of which overlaps radio coverage cell rl within a particular sector. In addition, the number and size of sectors may be set by the management system (not shown) of serving base station 1. The number of sectors may be different in each base station of the wireless network. A great number of sectors leads to a small number of base stations per list. Consequently, it is better to define a great number of sectors such that the mobile station will have to perform few signal strength measures during a handover.

As shown in the table represented on figure 2a, two different lists may comprise a different number of neighboring base station and redundancy is permitted since a neighboring base station may be included in two different lists.

Advantageously, the number and the size of the sectors are set such that the means size of all the lists is minimized. Depending of the topology of the wireless network (i.e. number and location of the neighboring base stations), it may be advantageous that the rings used to define the sectors have different width. (The width of the ring is the difference between the radius of two successive circles).

In addition, it may be advantageous that the difference between the number of neighboring base stations of the list including the largest number of neighboring base stations and the number of neighboring base stations of the list including the smallest number of neighboring base stations is minimized.

The adjustment of the size or of the number of sectors enables to avoid some sectors having a list including a very small number of neighboring base stations whereas some other sectors having large lists. Consequently, mobile station will be provided with lists including approximately the same number of neighboring base stations no matter the sector within which it is located when performing a handover.

Alternatively, the number or the size of the sectors is set to minimize the redundancy between the different lists. According to the method of the invention, for enabling the handover of a mobile station from the serving station to one of the neighboring base stations, the sector within which the mobile station is located is determined and the list associated to this sector is transmitted to the mobile station. In the case the serving base station comprises at least a directional antenna, as it has already been considered in the example illustrated by figure Ia, the determination of the sector is performed by determining the distance between the mobile station and the serving base station. The determination of such a distance may be performed by a measurement module 11 of serving base station 1, by interpreting, for instance, the results of power signal measures periodically performed and transmitted by a mobile station when performing a communication via a base station. After measurement module 11 has determined the distance between the mobile station and the serving base station, the determined distance may be transmitted to a neighbor list computation module 12 which uses this information to identify the sector within which the mobile station is located.

In one embodiment, the determined distance is compared with the different radius of the circles used to define the sectors. More precisely, when the determined distance is comprised between the radius circle ci and the radius of circle ci+1, the mobile station is considered to be located in the sector si corresponding to the intersection of the ellipse and the ring limited by circles ci and ci+1. Alternatively, neighbor list selection module 10 first computes, for each sector, the means value of the two radius of the successive circles used to defined the sector. Module 10 then computes the difference between the determined distance and each means value. The mobile station is considered to be located in the sector the means value of which minimizes the difference with the determined distance.

Referring to figure Ia and assuming that mobile stations 20, 21, 22 and 23 are getting out of radio coverage cell rl. Since distances d20 and d21 between mobile stations 20 and 21 and serving base station 1 are comprised between radius of circles c2 and c3, serving base station determines that they are both located in sector s3 and transmit list 13 to them. Mobile base station will then perform strength signal measurement only with base station associated with radio coverage cells r3, r4, r5 and r6. Conversely, mobile station 22 and 23 are provided with list Il which only includes three base stations. Since only a limited number of neighboring base stations is provided to mobile stations 20, 21, 22 and 23, strength measures with these neighboring base stations can be performed in a short and with a satisfactory accuracy.

As well illustrated on figure Ia, it is to be noticed that when such sectors are defined, the mobile station will be provided with a list which only includes the base stations under the radio coverage cell of which the mobile station is more likely to be located when definitively getting out of the radio coverage cells of the serving base station.

As described above with reference to figure Ia and 2a, all the mobile stations located at the same distance from the serving base station will be provided with the same list of neighboring base stations.

However, as shown on figure Ia although mobile stations 20 and 21 are provided with the same list I3, considering their respective current location in sector s3, it will be reasonably believed that the selected base station from the list to continue the communication will be different. Indeed, considering the location of mobile station 20, one can considers that the most adapted new base station is the base station associated with radio coverage r5. On the contrary, the future base station used to enable the continuation of the communication performed by mobile station 21 is certainly the base station associated with radio coverage r3.

Although the distances between serving base station and mobile stations 20 and 21 are approximately the same, they are located at two opposite border of radio coverage cell rl. The use of the direction of signal transmitted by mobile stations 20 and 21 and received by the antenna of serving base station 1 would be useful to reduce the number of neighboring base station included in the list without risking to remove from the list the most likely neighboring base station to be selected. Figure Ib represents the same radio coverage cell than figure Ia in which each sectors disclosed in figure Ia has been divided into two sectors according to the mains axis of the transmission/reception diagram of the directional antenna. More precisely, as shown on figure Ib, a sector corresponds to the part of the intersection, as defined when referring to figure Ia, which is located on the left side, respectively on the right side, of the main axis of the transmission/reception diagram of the directional antenna. Thus, with the same succession of circles c0, cl,..., c3, radio coverage cell rl of serving base station is divided into six sectors si, s2, ..., s6.

In the case each sector is only located on the left side or on the right side of the main axis, as illustrated by figure Ib, the determination of the sector in which is located the mobile station further comprises the direction of the signal transmitted from the mobile station and received at the serving base station.

Consequently, mobile stations 20 and 21, which were provided with the same initial list when only the distances between mobile stations and serving base station were taking into account, are, in the present case, providing with two different lists. These two different lists correspond to the initial list from which neighboring base station located on the other side of the main axis with respect to the side in which is located mobile station 20, respectively mobile station 21, have been removed.

Figure 2b represents a table comprising computed lists II, 12, ..., 16 respectively, associated with sectors si to s6 as illustrated on figure Ib. As shown in the table, sector s3 is associated with the list 13 including the neighboring base stations respectively associated with radio coverage cells r3 and r4. Similarly, list 14, associated with sector s4, includes the three neighboring base stations respectively associated with radio coverage cells r4, r5 and r6.

When radio coverage base station rl is divided in the manner illustrated on figure Ib, determining the sector in which the mobile station is located consists on performing an estimation of the distance between the serving base station and the mobile base station and performing an estimation of the direction of the signal transmitted from the mobile and received by the antenna.

The direction of the received signal may be performed by determining the angle existing between the direction of the received signal and the direction of the main axis of the transmission/reception diagram of the antenna.

In case the antenna consists in a plurality of transmission/reception radiating elements enable to be used according to a beamforming technique, the angle may be computed by an estimation of the time difference between the reception times of the signal emitted by the mobile station on two different radiating elements of the antenna.

Although the different technical features and advantages of the invention have been described with referring to the transmission/reception diagram of one specific directional antenna implemented in a base station, the invention is not limited to base station using only one directional antenna.

Indeed, currently used base stations are bisectorial or trisectorial. These base stations are implemented with two or three directional antennas and the radio coverage cell of the base station correspond to sum of the transmission/reception diagrams of each directional antenna. Dividing the radio coverage cell of the base station consists then in dividing each transmission/reception diagram respectively associated with one of the directional antenna implemented in the base station according to what have been disclosed when referring to figures Ia and Ib. A commonly located process can be used to determine both the position angle and the distance of the terminal from the antenna of the base station.

In other embodiment, the radio coverage cell of the serving base station may correspond to the transmission/reception diagram of an omni- directional antenna. In this case, each of said plurality of sectors corresponds to an angular sector of said transmission/reception diagram, and said current sector is determined based on an estimation of the angle between said mobile station and said omni-directional antenna.

Claims

1. A method for enhancing the handover of a mobile station (20-23) from a serving base station (1) of a cellular network to a new base station, said new base station being selected among a neighbor list including neighboring base stations, the radio coverage cell (r2-r8) of which overlaps the radio coverage eel! (rl) of said serving base station (1), said method comprising the steps of:
- Determining at the serving base station (1), the location of said mobile station (20-23) within the radio coverage cell (rl) of said serving base station (1) and
- Transmitting to said mobile station (20-23) a reduced neighbor list based on said location, characterized in that, said step of determining the location of said mobile station (20-23) comprises the sub-steps of:
- partitioning the radio coverage cell (rl) of said serving base station (1) in a plurality of sectors (sl-s3 ; sl-s6); and
- determining a current sector (sl-s3; sl-s6) in which said mobile station (20-23) is located among said plurality of sectors (sl-s3 ; sl- s6); and in that said reduced neighbor list includes only the neighboring base stations the radio coverage cell (r2-r8) of which overlaps said current sector (sl-s3; sl-s6).
2. The method as claimed in claim 1, characterized in that, the radio coverage cell (rl) of said serving base station (1) corresponding to the radio coverage beam of at least one directional transmitting/receiving antenna, said radio coverage beam extending along a main axis (al), said radio coverage beam is partitioned in a succession of ring portions extending concentrically with respect to said directional transmitting/receiving antenna along said main axis (al), in that each of said plurality of sectors (sl-s3) partitioning said radio coverage beam corresponds to one of said ring portion, and in that said current sector (sl-s3) is determined based on an estimation of the distance between said mobile station (20-23) and said directional transmitting/receiving antenna.
3. The method as claimed in claim 1, characterized in that, the radio coverage cell (rl) of said serving base station (1) corresponding to the radio coverage beam of at least one directional transmitting/receiving antenna, said radio coverage beam extending along a main axis (al), said radio coverage beam is partitioned in a succession of ring portions extending concentrically with respect to said directional transmitting/receiving antenna along said main axis (al), in that each of said plurality of sectors (sl-s6) partitioning said radio coverage beam corresponds to half part of one of said ring portion with respect to said main axis (al), and in that said current sector (sl-s6) is determined based on an estimation of the angle and of the distance between said mobile station (20-23) and said directional transmitting/receiving antenna.
4. The method as claimed in claims 2 or 3, characterized in that said estimation of the distance is based on results of signal strength measurements sent by said mobile station (20-23) to said serving base station (1).
5. The method as claimed in claim 3, characterized in that, said directional transmitting/receiving antenna including an array of radiating elements adapted to perform a transmission/reception according a beamforming technique, said estimation of the angle is based on the time difference between the reception times of the signal emitted by said mobile station (20-23) on two different radiating elements of said directional transmitting/receiving antenna.
6. The method as claimed in anyone of the preceding claims, further comprising the step of determining, for each sector of said plurality of sectors (sl-s3; sl-s6), a sector list including only the neighboring base stations the radio coverage cell (r2-r8) of which overlaps said sector.
7. The method as claimed in claim 6, further comprising:
- determining the number of neighboring base stations included into each sector list;
- modifying the size or the number of the sectors partitioning the radio coverage cell (rl) of said serving base station (1) in order to balance the number of neighboring base stations of each sector list.
8. The method as claimed in claim 2 to 5, characterized in that, the radio coverage cell (rl) of said serving base station (1) corresponding to a plurality of radio coverage beams of a plurality of directional transmitting/receiving antennas, the method is performed with the antenna of said plurality of directional transmitting/receiving antennas via which said mobile station (20-23) is carrying out the communication.
9. The method as claimed in claim 1, characterized in that, the radio coverage cell (rl) of said serving base station (1) corresponding to the transmission/reception diagram of an omni-directional antenna, each of said plurality of sectors corresponds to an angular sector of said transmission/reception diagram, and in that said current sector is determined based on an estimation of the angle between said mobile station (20-23) and said omni-directional antenna.
10. A base station (1) of a cellular network for carrying out the method as claimed in any one of claims 1 to 9, characterized in that it comprises
- tracing means (12) adapted to determine a current sector (sl-s3; sl-s6) in which is located said mobile station (20-23); and
- partitioning means (11, 13) adapted to include in said reduced neighbor list only the neighboring base stations the radio coverage cell (r2-r8) of which overlaps said current sector (sl-s3; sl-s6).
11. The base station (1) as claimed in claim 10 for carrying out the method as claimed in claim 6, characterized in that said partitioning means (11, 13) are further adapted to determine, for each sector of said plurality of sectors (sl-s3; sl-s6), a sector list including only the neighboring base stations the radio coverage cell (r2-rδ) of which overlaps said sector.
12. The base station (1) as claimed in claim 11 for carrying out the method as claimed in claim 7, characterized in that said partitioning means (11, 13) are further adapted to : - determining the number of neighboring base stations included into each sector list;
- modifying the size or the number of the sectors partitioning the radio coverage cell (rl) of said serving base station (1) in order to balance the number of neighboring base stations of each sector list.
PCT/EP2010/052425 2009-03-02 2010-02-25 Method for enhancing the handover of a mobile station and base station for carrying out the method WO2010100077A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP09305189.4A EP2227056B1 (en) 2009-03-02 2009-03-02 Method for enhancing the handover of a mobile station and base station for carrying out the method
EP09305189.4 2009-03-02

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR1020117018807A KR101286479B1 (en) 2009-03-02 2010-02-25 Method for enhancing the handover of a mobile station and base station for carrying out the method
CN201080009997.7A CN102342150B (en) 2009-03-02 2010-02-25 For strengthening the method for the switching of mobile radio station and the base station for performing the method
US13/254,253 US9002362B2 (en) 2009-03-02 2010-02-25 Method for enhancing the handover of a mobile station and base station for carrying out the method
JP2011552397A JP5705135B2 (en) 2009-03-02 2010-02-25 Method for enhancing the handover of a mobile station and a base station performing the method

Publications (1)

Publication Number Publication Date
WO2010100077A1 true WO2010100077A1 (en) 2010-09-10

Family

ID=41066326

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2010/052425 WO2010100077A1 (en) 2009-03-02 2010-02-25 Method for enhancing the handover of a mobile station and base station for carrying out the method

Country Status (6)

Country Link
US (1) US9002362B2 (en)
EP (1) EP2227056B1 (en)
JP (1) JP5705135B2 (en)
KR (1) KR101286479B1 (en)
CN (1) CN102342150B (en)
WO (1) WO2010100077A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014511602A (en) * 2011-02-14 2014-05-15 クゥアルコム・インコーポレイテッドQualcomm Incorporated In a wireless network using distributed remote radio heads, selecting an antenna port for a reference signal based on movement and CSI feedback
US8995400B2 (en) 2011-02-11 2015-03-31 Qualcomm Incorporated Method and apparatus for enabling channel and interference estimations in macro/RRH system
US9054842B2 (en) 2011-02-14 2015-06-09 Qualcomm Incorporated CRS (common reference signal) and CSI-RS (channel state information reference signal) transmission for remote radio heads (RRHs)
US9369930B2 (en) 2011-02-11 2016-06-14 Qualcomm Incorporated Cooperation and operation of macro node and remote radio head deployments in heterogeneous networks
US9544108B2 (en) 2011-02-11 2017-01-10 Qualcomm Incorporated Method and apparatus for enabling channel and interference estimations in macro/RRH system

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5713022B2 (en) * 2010-10-12 2015-05-07 日本電気株式会社 Wireless communication system, wireless communication method, mobile station, control method, and base station
US8831608B2 (en) * 2010-10-25 2014-09-09 Acer Incorporated Apparatuses, systems, and methods for inbound handover enhancement
WO2012142602A1 (en) * 2011-04-15 2012-10-18 Airsage, Inc. Mobile device location estimation using operational data of a wireless network
US20140302796A1 (en) * 2013-04-09 2014-10-09 Eden Rock Communications, Llc Downlink interference detection using transmission matrices
KR101486758B1 (en) * 2013-04-16 2015-01-29 한국과학기술원 Handover method in communication system based on Beam Division Multiple Access and mobile station performing the method
US9451513B2 (en) * 2013-06-18 2016-09-20 Blackberry Limited Geographically-organized neighbor cell lists
CN107735854A (en) 2014-12-26 2018-02-23 汉高股份有限及两合公司 Sinterable jointing material and use its semiconductor device
WO2019011427A1 (en) * 2017-07-12 2019-01-17 Telefonaktiebolaget Lm Ericsson (Publ) Altitude dependent neighbour relations in a wireless communication network

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996007108A1 (en) * 1994-08-31 1996-03-07 Motorola Inc. Method and apparatus for conveying a communication signal between a communication unit and a base site
WO1999027657A1 (en) 1997-11-25 1999-06-03 Motorola Inc. Method and apparatus for determining hand-off candidates in a neighbor set in a cdma communication system
US6061337A (en) * 1996-12-02 2000-05-09 Lucent Technologies Inc. System and method for CDMA handoff using telemetry to determine the need for handoff and to select the destination cell site
EP1056304A2 (en) * 1999-05-27 2000-11-29 Nortel Networks Limited Narrow beam traffic channel assignment method and apparatus
WO2001069949A1 (en) * 2000-03-15 2001-09-20 Verizon Laboratories Inc. Method and system for determining a neighbor list for a code division multiple access (cdma) sector
US7092722B1 (en) 2001-07-26 2006-08-15 Sprint Spectrum L.P. Method and system for establishing mobile station active set based on mobile station location

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4718081A (en) * 1986-11-13 1988-01-05 General Electric Company Method and apparatus for reducing handoff errors in a cellular radio telephone communications system
FI105515B (en) 1995-05-24 2000-08-31 Nokia Networks Oy The method to speed up the handover, as well as a cellular radio system
JP2001197551A (en) * 2000-01-12 2001-07-19 Ntt Docomo Inc Mobile communication system and method for configuring cell sector for the mobile communication system
KR20050000368A (en) * 2002-03-08 2005-01-03 아이피알 라이센싱, 인코포레이티드 Antenna adaptation to manage the active set to manipulate soft hand-off regions
JP4073812B2 (en) * 2003-03-27 2008-04-09 京セラ株式会社 Communication control method, base station information creation device
KR100706904B1 (en) * 2005-07-28 2007-04-12 에스케이 텔레콤주식회사 Apparatus and Method for Analyzing Coverage of Sector Using Field Data
KR101289906B1 (en) * 2005-10-06 2013-07-26 삼성전자주식회사 A method for finding geographically neighboring access points
KR100653529B1 (en) 2005-12-14 2006-11-27 주식회사 케이티프리텔 Method and apparatus for optimizing neighbor list automatically in asynchronous w-cdma network

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1996007108A1 (en) * 1994-08-31 1996-03-07 Motorola Inc. Method and apparatus for conveying a communication signal between a communication unit and a base site
US6061337A (en) * 1996-12-02 2000-05-09 Lucent Technologies Inc. System and method for CDMA handoff using telemetry to determine the need for handoff and to select the destination cell site
WO1999027657A1 (en) 1997-11-25 1999-06-03 Motorola Inc. Method and apparatus for determining hand-off candidates in a neighbor set in a cdma communication system
EP1056304A2 (en) * 1999-05-27 2000-11-29 Nortel Networks Limited Narrow beam traffic channel assignment method and apparatus
WO2001069949A1 (en) * 2000-03-15 2001-09-20 Verizon Laboratories Inc. Method and system for determining a neighbor list for a code division multiple access (cdma) sector
US7092722B1 (en) 2001-07-26 2006-08-15 Sprint Spectrum L.P. Method and system for establishing mobile station active set based on mobile station location

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9544108B2 (en) 2011-02-11 2017-01-10 Qualcomm Incorporated Method and apparatus for enabling channel and interference estimations in macro/RRH system
US8995400B2 (en) 2011-02-11 2015-03-31 Qualcomm Incorporated Method and apparatus for enabling channel and interference estimations in macro/RRH system
US9357557B2 (en) 2011-02-11 2016-05-31 Qualcomm Incorporated Method and apparatus for enabling channel and interference estimations in macro/RRH system
US9369930B2 (en) 2011-02-11 2016-06-14 Qualcomm Incorporated Cooperation and operation of macro node and remote radio head deployments in heterogeneous networks
US9426703B2 (en) 2011-02-11 2016-08-23 Qualcomm Incorporated Cooperation and operation of macro node and remote radio head deployments in heterogeneous networks
US9054842B2 (en) 2011-02-14 2015-06-09 Qualcomm Incorporated CRS (common reference signal) and CSI-RS (channel state information reference signal) transmission for remote radio heads (RRHs)
JP2014511602A (en) * 2011-02-14 2014-05-15 クゥアルコム・インコーポレイテッドQualcomm Incorporated In a wireless network using distributed remote radio heads, selecting an antenna port for a reference signal based on movement and CSI feedback

Also Published As

Publication number Publication date
KR20110105394A (en) 2011-09-26
US9002362B2 (en) 2015-04-07
US20130260769A1 (en) 2013-10-03
JP2012519443A (en) 2012-08-23
CN102342150B (en) 2015-09-02
EP2227056A1 (en) 2010-09-08
KR101286479B1 (en) 2013-07-16
JP5705135B2 (en) 2015-04-22
CN102342150A (en) 2012-02-01
EP2227056B1 (en) 2019-04-24

Similar Documents

Publication Publication Date Title
US7016702B2 (en) System and method utilizing dynamic beam forming for wireless communication signals
KR100883943B1 (en) Wireless communications with an adaptive antenna array
TWI471028B (en) Method and wireless transmit/receive unit for facilitating handover
FI105596B (en) Method for determining the location of the mobile station
US5828661A (en) Method and apparatus for providing a cone of silence in a cellular communication system
CA2364777C (en) Preservation of cell borders at hand-off within a smart antenna cellular system
US6760599B1 (en) Method and apparatus for selecting a base station
US5953661A (en) Method of maximizing spectral efficiency in a cellular communications system
EP0956679B1 (en) Method and apparatus for performing mobile assisted hard handoff between communication systems
JP4643600B2 (en) Method and apparatus for providing diversity in hard handoff for CDMA systems
US7684802B2 (en) Communications handoff using an adaptive antenna
JP3887013B2 (en) Method and apparatus for communicating communication signals between a communication unit and a base site
US8787907B2 (en) Frequency selection and transition over white space
EP0951793B1 (en) Method and apparatus for hard handoff in a cdma system
KR100368704B1 (en) Method and apparatus for determining hand-off candidates in a communication system
EP0830765B1 (en) Method of using an access point adjacency matrix to establish handoff in a wireless lan
US6850502B1 (en) Join process method for admitting a node to a wireless mesh network
ES2531970T3 (en) Communications system via mobile telephony and method to provide common channel coverage using beam-forming antennas
JP5001160B2 (en) Wireless terminal positioning using apparatus and method with carrier diversity
US20040152480A1 (en) Method and apparatus for generating a neighbor cell list
DE69233707T2 (en) Cordless communication system with multiple access through space multiplexing
CN101395892B (en) Method and system for utilizing smart antennas in establishing a backhaul network
US5917811A (en) Method and apparatus for measurement directed hard handoff in a CDMA system
US20030139188A1 (en) Geolocation using enhanced timing advance techniques
US7043274B2 (en) System for efficiently providing coverage of a sectorized cell for common and dedicated channels utilizing beam forming and sweeping

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201080009997.7

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10705874

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase in:

Ref document number: 20117018807

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase in:

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2011552397

Country of ref document: JP

122 Ep: pct application non-entry in european phase

Ref document number: 10705874

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 13254253

Country of ref document: US